U2 have cancelled their US tour and headline slot at Glastonbury after singer Bono was told to rest for at least two months following emergency spinal surgery.

The singer said he was “heartbroken” after pulling out of the show, which had been booked to mark the festival's 40th anniversary.

Bono suffered a back injury last week and was discharged from hospital in Munich, Germany, on Monday. He has been told by doctors to undertake a rehab regime as well as resting for at least eight weeks.

The band have also been forced to postpone 16 shows on the North American leg of their U2 360 tour.

Bono called Glastonbury organiser Michael Eavis on Monday to explain that the band would be unable to play.

He said: “I'm heartbroken. We even wrote a song especially for the festival.”